Brief Description of PPR - #Introduction #symptoms #PPR virus #PPRV characteristics #Genome organization of PPRV-Structural and non structural proteins #Pathogenesis #PPRV diagnostic methods- Serological & Nucleic acid based test #Vaccine #Treatment #Control

1. Peste des Petitis Ruminants (PPR)
BY-
Arshi goyal
M.D.U Rohtak

2. PPR
•A Peste des petites is an acute, highly ingenious and
transboundary viral disease of goat, sheep and wild ruminants.
• This disease is also known as ‘goat plague’ or ‘ovine rinderpest’.
• Having high morbidity and mortality rate.
• Death rate can be high as 80% in infected animals.
• It is nowadays widely causing disease in dogs and camels also.

3. • First time isolation of virus was done in 1962 from sheep cell
culture and was observed under electron microscope in 1967.
• PPRV most commonly affect goat and sheep population.
Comparatively disease is more severe in goat than sheep.
• It has been observed that PPR virus is most lethal to the
animals belonging to the age group 4-18 or up to 24 months.
• Cattle and buffalo are seroconvert but do not transmit
disease.
• The PPRV does not infect humans.

4. • High fever
• Sudden depression
• Mouth erosive lesions
• Conjunctivitis
• Oculo-nasal discharge
• Necrotizing
• Severe diarrhoea
• Bronchopneumonia

5. Pirulent eye and
nose discharge
congestion of conjunctiva Early mouth lesions
showing areas of dead
cells
swollen, crumble lips; later mouth lesions
signs of diarrhoea The
hindquarters are soiled
with liquid faeces

6. PPR virus
• PPR virus contains a lipid bilayer envelop that is derived from plasma
membrane of host cell.
• Containing RNA as a genome.
• Belongs to the order mononigavirales
family paramyxoviridae
genus morbilivirus
• It has genetically 4 distinct lineages (I, II, III, IV)-
•western and central Africa.
Lineage
I,II
• Eastern Africa, the Arabian
peninsulaLineage III
•Northern Africa and middle east
•Southeast AsiaLineage IV

7. •CharacteristicsPPRV
WHO
For its
inactivation
Temperature
>70c
For its
inactivation
PH <5.6
or>9.6
Can survive
in salted or
frozen meat
Sensitive to
UV light

8. Genome organization of PPRV
• The PPRV containing RNA as a genome which is single stranded,
non segmented, negative strand , and consists of 15, 948
nucleotides.
• It is divided into 6 transcriptional units that encodes for the six
structural proteins-
 N (Nucleoprotein),
 P (Phosphoprotein),
 M (Matrix protein),
 F (Fusion protein),
 H (Haemagglutinin protein),
 L (large polymerase protein )
And two non-structural proteins- V and C.

9. Different types of gene that encode
proteins of virus
3’Leader
N
1674nts
P/C/V
1530nts
M
1008nts
F
1641nts
H
1830nts
L
6552nts
Trailer5
Structural proteins
Non Structural
proteins
Nucleoprotein
Phospho protein
NSP,C and V
Matrix
protein
Fusion
protein
Hemagglutinin Large protein
Non coding
sequence

10. Structural proteins
N (Nucleocapsid Protein)
• PPRV genome is encapsulated by N protein into ribonucleoprotein (RNP)
complex ranges in size from 489-553 Amino acid.
• Molecular wt. is 58 KDa.
• It is one of the viral protein in PPRV that is produced in higher amount in
morbilivirus.
• N protein can be generally divided into two main structural regions:
a) Ncore - a N-terminal domain having three- fourths of the protein conserved
in sequence among related viruses.
b) Ntail- a C-terminal non conserved acidic domain.

11. P (Phosphoprotein)
• The P protein is the only P/V/C gene product that is essential for viral
RNA synthesis also a component of the RNP .
• The molecular weight of P protein is 60 kDa.
• The length of PPRV P protein is 509 amino acids and is highly
phosphorylated at serine and threonine residues within the N terminal
region.
• At C terminal, it behaves as a co-factor for the RNA-dependent RNA
polymerase (RdRp) which is well conserved in secondary structure for all
viruses of paramyxoviridae.
• This protein is the least conserved among morbilivirus .
• But at position 151 of Serine residue (phosphorylated) is highly
conserved among the morbiliviruses .

12. M (Matrix Protein)
• Matrix protein is the most abundant protein in the viron having 91%
amino-acid identity level.
• The molecular weight of P protein is about 38 kDa.
• It is the most conserved viral protein within the morbiliviruses.
• M proteins contain 341 to 375 residues and are quit basic proteins.
• M protein interacts with N protein, surface glycoprotein (H and F) and with
the RNP complex in the cytoplasm .
• Due to the abundance of basic amino acid in M protein, plays their
important role in ionic interaction with the acidic N proteins.

13. F (Fusion Protein)
• The Fusion protein is crucial for the formation of spike on the
envelope surface of PPRV.
• Has molecular weight of 59.1 kDa.
• F gene encodes 540 to 580 residues.
• It plays vital roles during the initial steps of virus replication.
• In morbilivirus, F and H Protein play a significant role in the
attachment of virus to the membrane of host that provides a path to
enter nucleocapsid into the cell cytoplasm.
• But only the F protein necessarily required for fusion rather than
both protein in case of PPRV .

14. H (Hemagglutinin Protein)
• The H protein of virus has both the activity of hemagglutinin and
neuraminidase.
• The molecular weight of PPRV HN protein is 67 kDa.
• The HN protein plays major role in the attachment of virus to
host cell as well as enhance the initiation of cleavage of sialic acid
residue at the carbohydrate moiety (glycoprotein) of the host.
• H protein is less conserved among different strains.

15. L (Large Protein)
• The L protein is essential component of RNP which plays a major role
in viral RNA synthesis
• Molecular weight of about 247.3 kDa having ~2200 amino acid in
length.
• It was observed that the amino acid shares the similarity B/W PPPV
and RPV L proteins of approx.70.7% .
• It is the largest viral protein and is generally found in low amount in
the infected cells.
• The N and C terminal regions of L protein are diverse, but six highly
conserved domains are found near middle of polypeptide of all
paramyxoviruses .

16. Non-structural Proteins
C Protein
• Two non-structural proteins (C and V) are also found in addition to
six structural proteins.
• These are quit conserved proteins.
• The C protein is about 20 kDa and is not phosphorylated.
• The C protein shows high degree of similarity with the other viruses
of same order.
• C Protein is located exclusively in the cytoplasmic region.

17. V Protein
• The molecular weight of V protein is ~ 25-30 KDa.
• Among paramyxoviruses, the histidine and cysteine residues are
highly conserved at C terminal end of V protein that binds two zinc
molecules.
• V protein is an accessory protein that plays vital role in the
pathogenesis and replication of virus
• Functions by inhibiting the viral RNA synthesis for measles virus V
protein.

18. Pathogenesis of PPRV

19. Stepwise representation of PPRV Pathogenesis
(A) Virus first enter the host through airways and infect tissues (Produce IFN ),
later migrate to respiratory tract, where they infect APC, DC, macrophages
(play important role in pathogenesis) and monocytes. Due to the induction of
IFN, APC migrate to lymph nodes then to other lymphatic organs such as
Payer’s patch and spleen through circulatory system .
(B) After reaching APC to their respective places (lymphatic organs), PPRV again
replicate and cause cell death. Due to the blockage of IFN response and
signalling, suppresses immune response of host.

20. (C) Dissemination of the PPRV virus takes place distantly
(lymphatic tissues such as spleen, payer’s patches etc.) where
they further starts replication and increase viral load.
(D) Finally PPRV infect epithelial tissues where the symptoms
appeared such as pneumonia, gastroenteritis but the virus
shedding starts prior the symptom appear.

21. PPRV diagnostic methods
Serological test Nucleic acid based test
Agarose based immuno RT-PCR
diffusion technique (AGIDT)
Immunocapture ELISA ( ICE) Multiplex RT PCRs
Haemagglutination (HA) tests ) Multiplex RT qPCRs
Immunochromatographic test ELISAs
Loop mediated isothermal
Amplification (LAMP)

22. Serological test
1. Agarose based immuno diffusion technique (AGIDT)
It works on the principle of diffusion of antigen and antibody
in agar medium for the detection of virus antigens. It is easy,
fast and cost effective process. Limitation of using this
technique is that it does not able to differentiate between
the antigenically similar viruses.
2. Immunocapture ELISA (ICE)
Virus antigens can also be detected by immunocapture ELISA
(ICE).It works on the principle of formation of precipitin line.
It is most rapid test and can differentiate between the
antigenically similar viruses.

23. 3. Haemagglutination (HA) tests
It was based on the property of H protein, performed in
1991. This test is simple and cheap, does not require
specialised instruments to perform . But the major limitation
is that it does not detect early and mild stage of disease.
4. Immunochromatographic test
It detects interaction of antigen and antibody on a paper also
called as Lateral flow test. It is simple nitro cellulose based
device which is prespotted with antigen/antibody that
detects the presence of unknown antigen/antibody (Analyte)
in liquid sample.
This test is quick, easy to perform without the need for
specialized and costly equipments.

24. Nucleic acid based test
1. RT PCR
In 2002, this method was used to detect virus based on reverse
transcription which require expertise to perform. Detection
was done on N and F gene. Cost is high; it is now one of the
tests used most frequently. It is not able to detect the large
sample size, sensitive to cross contamination.
2. Multiplex RT PCRs
This assay used multiple primers to target the N and M genes
for the detection and differentiation of viruses having higher
sensitivity.
3. Multiplex RT-qPCR
This assay used multiple primers to detect and differentiate
many respiratory diseases of small ruminants but having low
detection limit, time and was cost effective.

25. 4. ELISAs
In ELISA, the antigen and antibody interaction takes place which is viewed
by presence of chromogenic substrate, which is then converted into product
by enzyme like horseradish peroxidise (HRP) tagged on antibody bound to
epitope of PPRV antigen for the detection of Antigen .Some other technique
such as competitive and blocking ELISA are also used for monitoring of virus
with greater sensitivity and specificity .These assays were performed using
anti-H MAbs. It is best method for detection of virus for large numbers of
serum sample it is easy, quick, cheaper, assays for diagnosis.
5. LOOP MEDIATED ISOTHERMAL AMPLIFICATION (LAMP)
In LAMP based technique at least four primers were used to target the M
and N gene at six different regions for the amplification. Bst DNA
polymerase (Bacillus sterothermophilus) is used in place of Taq polymerase
It is a simple, fast, specific, with lack of expertise. It is very sensitive
technique, with greater sensitivity than RT-PCR Moreover, the one and two
step LAMP assay are also developed for the detection of target M gene and
N gene to reduce the problem of cross-contamination with the sample but
gives false positive result. It cannot work with complex samples. It is the
only diagnostic tool which cannot be used for cloning like PCR.

26. • Various types of PPR vaccines are now developed, such as live-attenuated,
inactivated killed, vector based, recombinant, protein based, have been
developed. Among them live-attenuated PPR vaccines are considered to be
the best for disease prevention in endemic regions .
• In 1989, the first protective live attenuated PPR - derived from Nigeria/75
strain belonged to lineage II and Sungri/96 strain belonged to lineage IV.
• In India S96 vaccine is commonly used, provide immunity against 2 Indian
strains only whereas N75 vaccine is used worldwide and thus provide
immunity against all the 4 lineages .
• Production of DIVA vaccines by recombination technique having higher
cross-protective ability .
• A tissue culture based vaccine was recently developed in 2001 by
Bangladesh Livestock Research Institute (BLRI)
•

27. •Proper disposal from affected areas
should be needed.
•Antibiotics such as-
Chloramphenicol
Chlortetracycline
Penicillin
oxytetracycline
streptomycin
recommended for treatment to prevent further bacterial infections
given for 5–7 days.
Anti-diarrhoeal medicine or oral rehydration fluid are preferred
to balance the level of electrolytes in body to treat diarrhoea.

28. • Restrict the movement of animals from infected flock to
prevent the spread of infection.
• Decontaminate the contaminated areas with a solution of high
and low pH.
• Proper cleaning of bedding area where domestic animals stays.
• Dead animals should be buried or burned earlier before the
chances of infection increased.
• For the examination of sick animals contact to Veterinarian and
thus educate the employees how to handle the infected animals.